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A Circularly Polarized Corner Reflector Antenna, Walter Ronald Koenig

Masters Theses

"Image theory is used to develop the far field and polarization equations for a ninety degree corner reflector antenna. These equations are in terms of spherical coordinates, the length of the dipole element, the distance of the dipole from the corner of the reflector, and the angle of tilt of the dipole element with the apex of the corner. The equations are simplified to give the far fields in the vertical and horizontal planes for the special case of a half-wavelength dipole. An expression to calculate the distance of the dipole from the corner necessary to give circular polarization broadside …

Design Of Non-Uniform Linear Antenna Arrays With Digitized Spacing And Amplitude Levels, Jack F. Morris

Masters Theses

"Recent developments in space exploration have shown a need for high resolution, high gain antennas. The introduction of non-uniform linear array theory has provided a means by which arrays may be designed to produce narrow main beams with fewer elements than required by uniform arrays. A general theory has not been developed, however, and the design engineer has been left with only trial-and-error methods with which to work. In this study a technique has been developed by which non-uniform antenna arrays may be synthesized to meet a given set of specifications with reasonable accuracy. The elements of the array are …

Optimum Finite Memory Nonlinear Filter, Ching-Chyoun Yang

Masters Theses

"This thesis investigates the possibility of using the Zadah theory and a machine type computer to design an optimum finite memory nonlinear filter for extraction of Poisson distributed signal pulses from a background of Gaussian noise. Basically the procedure involves the technique of solving simultaneous equations by the computer. We demonstrate that it is possible to find the limitation of the filter of class N₁ in terms of an absolute minimum mean square error. However, due to the capacity of the computer we do not actually determine the absolute minimum. Nevertheless we do show that the mean square error decreases …

Linvill's Model As Applied To P-N Junction Photo-Diodes, Rudy Michael Chittenden

Masters Theses

"The problem undertaken in this study is to present a performance evaluation of Linvill's model as it pertains to the p-n junction photo-diode. The evaluation is performed by comparing the distributed mathematical solutions, the solution obtained using Linvill's lumped model, and the experimental measurement of the transient voltage rise across a photo-diode due to a unit-step pulse of light incident on the junction. Despite the absence of a suitable light source for use in the experimental measurement, it is concluded that Linvill's model provides an excellent means to determine the risetime of a photo-diode. This is provided that the photo-diode …

On Time-Optimal Second Order Discrete Control Systems, Chao-Tai Li

Masters Theses

"The time optimal control problem in unforced discrete systems is studied in this thesis. Comparison is made between the discrete and the continuous control systems by means of minimum time isochrones. concerning optimal time, it is shown that using the discrete control system will take at most one more sampling period of time to go to equilibrium. An investigation is also made for the case when the time constant of the physical plant, G(s), and the control model are different. In such a case, an optimal trajectory can not be obtained. An adaptive process is proposed to adjust the model …

An Evaluation Of Demonstrations On Inductor Theory, Boyd Warner Wasson

Dissertations and Theses @ UNI

The writer sought an improved approach for teaching theory of electronics to high school students. This approach was intended to require less expense and time needed to provide classroom instruction on electrical theory.

The purpose of this study were to:

(1) Prepare a number of demonstrations to illustrate phenomena associated with coils or inductors and their use in practical electronics.

(2) Prepare equipment and gather parts needed to perform demonstrations. Ease of construction and economy were important considerations.

(3) Evaluate the effectiveness of the demonstrations on student comprehension and the ability to apply information taught.

Stability Determination By Liapunov's Method In Nonlinear Control Systems, Neng-Chung Liao

Masters Theses

"An introduction to Liapunov's second method as it applies to control system stability is presented in this work. Main theorems and definitions of Liapunov's method are treated. In particular, Lur'e's method and Szego's method for testing the stability of a nonlinear system are presented, and several examples are used to illustrate these procedures"--Abstract, page ii.

Analog Computer Study Of Unequally Spaced Antenna Arrays, Fred M. Dickey

Masters Theses

"The problem undertaken in this thesis was to study the basic properties of unequally spaced antenna arrays. The study was done on a trial and error basis by simulating the expression for the far field pattern of a general array on an analog computer. Many patterns were obtained from the analog computer for the purpose of comparison. The patterns of two spacing schemes that are typical of unequally spaced arrays are presented for the purpose of illustration"--Abstract, page ii.

A Study Of Electro-Magnetic Wave Propagation In Inhomogeneous Media, Thomas N. C. Wang

Electrical and Computer Engineering ETDs

The central problem of this work will be the development of several approximation methods and the application thereof to the solution of second order linear differential equations which arise in connection with the propagation of electromagnetic radiation in inhomogeneous media. Chapter I is an introduction to the problem. Maxwell’s equations are written down and it is assumed that both σ, the conductivity, and ɛ, the permittivity, are scalar functions or position. Often the above function characterizing some or the properties of matter vary in physical situations. For example, in waveguides, there may be inserted layers of dielectric material along the …

The Design Criteria Of A Phoswich Transducer., Richard L. Crawford

Electrical and Computer Engineering ETDs

This dissertation is an experimental and theoretical treatise on the design criteria of a phoswich transducer. The major emphasis is on the application in a gamma-ray spectrometer. The conversion efficiency, gamma-ray cross sections, response to charged particles, luminescence decay time, spectral response and physical qualities are discussed, in considerable detail, in making the optimum choices for the inorganic crystal and the organic phosphor which will act as the charged particle anticoincident shield. The effect of the thickness of the anticoincident shield on resolution, the percentage of gamma-rays absorbed, the percentage of gamma-rays that are atten­uated in energy and the lower …

On Optimum Receiver Using Decision Theory, Philip T. Tai

Masters Theses

“In recent years communication engineers have given increased attention to the study of communication through random media. The name random is used to describe a medium the properties of which are stated only in a statistical sense. For example the impulsive response of a certain medium may only be known as one of an ensemble of possible impulsive responses; the particular member of interest being drawn up according to some statistical rule. In other words there exists some "uncertainty" concerning the characteristic description of the medium. Significant work on these problems has been done by Price and Turin. Related work …

An Analysis Of The Simulated Inductande Obtained From Forward Biased Semiconductor Diodes., Everett Harold Vannoy

Masters Theses

"The problem undertaken in this thesis is to study the simulated inductance observed in forward-biased abrupt junction p-n diodes with a highly doped p region and a nearly intrinsic n region and show that it is due to conductivity modulation. Unlike other analyses of this phenomenon, a voltage step is applied to the diode in such a direction as to forward bias it and the behavior of the injected minority carriers are observed. By comparing the resultant current through the diode to the relationship predicted by the equivalent circuit of the diode, an expression is obtained for the simulated inductance. …

The Resolution Of Two Known Signals In White Gaussian Noise., Peter Cheng-Fang Wang

Masters Theses

"The problem of resolving two signals F1(t) and F2(t) in white Gaussian noise n(t) is treated here as a problem in statistical decision theory. We assume a situation in which one of two similar signals is present and an observer is asked to make a decision concerning which of the signals is present with a tolerable probability of error. The observer is allowed to use the best system which he can design for this particular purpose. Of course, this observation will be disturbed by noise and therefore, the observer is led to ambiguous selections. It is apparent that the optimum …

Optimum Zero-Memory Nonlinear Filter, Benjamin Shaw-Hu Wang

Masters Theses

“The purpose of this report is to review the basic work described by Zadeh insofar as systems of class N₁ are concerned and to apply his general results to a specific problem in which a non-linear filter is mandatory simply because the linear filter is essentially ineffective. The ineffectiveness stems from the fact that the autocorrelation function of the signal plus the noise has essentially the same variational character as the signal alone. Therefore, the transfer function of the linear filter turns out to be simply a constant. Thus, the output of the linear filter is just an attenuated …

Compensator Design For Unity Feedback Systems Using An Analytical Method, Chang-Yu Wu

Masters Theses

“In control systems engineering it is frequently necessary to compensate a fixed plant whose transfer function cannot be changed. Usually the characteristics of the resulting system are established in terms of steady-state and transient performance specifications. Generally it is necessary to insert a compensator which insures stability as well as satisfies the specifications.

In this thesis an analytical method is developed to determine the transfer function of the compensator in order to satisfy the following set of specifications. The fixed system is assumed to contain one non-linearity, saturation. The input to the saturable device is constrained in a statistical …

Artifact Filter., Kent William Swearingen

Masters Theses

"Peripheral blood pulse monitors are highly susceptible to noise-artifact-- in their present stage of development. The purpose of this thesis is to demonstrate a feasible means for filtering the artifact, using existing monitors. Since no peripheral pulse monitor (transducer) was available for experimentation, a simulated test input was devised with frequency variations from JO cycles/minute to 1.50 cycles/minute.

The filtering circuit predicts the time location of each input pulse. The location of the prediction is governed by the accuracy of the preceding prediction. This is controlled by an R-C timing circuit with a Schmitt Trigger and relay.

From the data …

An Investigation Of The Adaptability Of The Linvill Model For Transistor Synthesis, John A. Reagan

Masters Theses

"The Linvill transistor model may be used for transistor synthesis if the model accurately approximates transistor response and may be readily simulated on an analog computer. Experiments were performed on a transistor to determine the Linvill model parameters. The transistor's large-signal transient response was investigated by pulsing the emitter with a current that drove the transistor from the active region of operation into saturation. The same problem solved experimentally was then solved analytically by replacing the transistor with the Linvill model. The experiment was then simulated on an analog computer by using the equations that govern the Linvill model's response. …

Time Optimum Switching Zones In Multiple-Valued Control Systems, Jack Leroy Crawford

Masters Theses

"Present control system theory provides the criteria necessary to bring a second-order single-valued system to rest in a minimum time after a step input. The bang-bang type controller has been developed to obtain this optimum response.

However, existing theory fails to provide the necessary information to obtain the optimum response from a second-order rotational system when multiple values of angular position are allowed. This thesis extends the control theory to include these multiple-valued systems by showing the existence of what are called optimum switching zones. These zones predict which of the infinite number of switching curves in a multiple-valued system …

Real Time Testing With A Time Scaled Analog Computer., Wayne F. Balsman

Masters Theses

"A present limitation to the testing of a physical subsystem within an analog simulation is that the analog computer must compute in real time. If it is necessary to time scale the simulation of the complete system, a physical subsystem of the complete subsystem may not be tested within the simulation. Therefore, a means of changing the time scale of the analog signal is needed to test a physical subsystem within a time scaled analog computer simulation.

In this thesis a means of time conversion by sampling the analog signal at one rate, storing the samples, and reading the samples …

A Five Dimensional Field Theory., Scott Holzhauser

Electrical and Computer Engineering ETDs

Several authors in the past have utilized the five dimensional manifold to accomplish their ends, as the next few sections explain. The ends are frequently different, however, Corben1,2 relates his fifth dimensional variables to rest quantities, such as the "rest mass density" and "rest charge density." Flint3,4,5 uses x as an unobservable 5 cyclic coordinate, and Ingraham6 interprets x as a "parameter of finiteness" that keeps finite the usual field quantities.

Transistorized Circuits For Telemetry, Dominick Misciascio Jr.

Physics & Astronomy ETDs

This thesis is concerned with the telemetry of small DC signals from photomultiplier tubes. The circuitry must have a high input impedance so as not to load down the photomultiplier tube and a low output impedance which is capable of controlling the current through a small incandescent bulb. This bulb is used to illuminate a photoresistor. The output of the circuit consists of a variation of the resistance of the photoresistor. This variable resistance is conventionally converted into a variable audio frequency which is transmitted to the receiving station on a radio-frequency carrier. The output resistance must be independent of …

Measurement Of Thin Film Thickness By The Crystal Resonance Method, David G. Adams

Electrical and Computer Engineering ETDs

Recent years have seen a tremendous increase in thin film activity. The electronics industry, in particular, has become increasingly active in the development and production of thin film components and complete micro-electronic circuits laid down as thin films. The principal methods of producing thin films are by chemical and electrolytic processes, and by evaporation and sputtering in vacuum. One of the problems associated with film deposition in vacuum involves the measurement of film thickness, a difficult task because: 1) the thicknesses encountered are typically measured in hundreds of angstroms; 2) the films are not physically flat; and 3) they do …

Determining Stability Of Nonlinear Control Systems Via Lyapunov's Method., John Joseph Komo

Masters Theses

"The problem undertaken in this thesis is to present Lyapunov's method of stability as i t applies to control systems and to use it in the stability analysis of nonlinear control systems. The variable gradient method of generating Lyapunov functions is presented since this seems the best general procedure for obtaining Lyapunov functions. Also, the integration of matrices method is presented as a comparison. ii

Procedures for the use of the variable gradient method and the integration of matrices method are written and several examples are used to illustrate these procedures.

It is concluded that Lyapunov's method is very definitely …

A Time Optimum Bang Bang Control System Under Specified Inputs., John F. Curtin

Masters Theses

"The problem presented is a study, by simulation on an analog computer, of a time optimum "bang bang" control system with a second order plant. Phase plane analysis techniques are used to describe the performance of the second order plant under the action of a maximum effort controller. From this, the system logic is developed for time optimum response to a step reference input. A fast time model of the plant is used to obtain repeated high-speed extrapolations of the plant outputs, at the same time a linear predictor generates future values of the reference. The error functions thus found …

Linear System Transfer Function Identification, Tuh-Kai Koo

Masters Theses

“An approach using a high speed special purpose digital computer to identify the transfer function of a linear system is presented in this thesis. The data for computation are obtained by measuring the system response and its derivatives periodically with a periodic test signal (impulse) input.

The order of the system is first determined by evaluating the rank of a Hankel matrix. Then, the transfer function is determined by solving two sets of system equations.

Theoretical analysis is emphasized in the study. Two examples are given for the purpose of illustrating the theory

Small Signal Gain Analysis For A Seven Cavity Klystron Amplifier., William E. Hord

Masters Theses

"The problem was to find a suitable method of using the digital computer to calculate the small signal gain characteristics of a seven cavity klystron amplifier. Background material relevant to the problem was reviewed. The differential equations for small signal conditions in a gridless gap klystron were developed. These equations were then solved and put in a matrix form suitable for digital computer analysis. Suggestions for additional development were proposed"--Abstract p. ii

Infrared Modulation Using The Field-Effect Properties Of Germanium., Lloyd E. Brunkhorst

Masters Theses

"The absorption of infrared radiation, by free carriers in germanium, has been used to amplitude modulate infrared radiation. In the experiment, a space charge layer consisting of free carriers is established at the inner surface of a germanium sample by using the field-effect technique. Infrared radiation of a wavelength to which the germanium is transparent is then Internally reflected from this surface. The infrared radiation passes twice through the space charge layer for each internal reflection. With each pass through the space charge layer, the amplitude of the transmitted infrared is decreased. Amplitude modulation of the transmitted infrared is accomplished …

Pattern Calculations On A Loaded Spiral Antenna., Jose Briceno

Masters Theses

"The purpose of this thesis is to calculate and p lot the radiation patterns o f a ferrotron-loaded spiral antenna made of semicircles. In particular, this work is confined to a balanced spiral free to radiate in all directions.

The current distribution used in the evaluation of the vector potential is taken from a synthesized current obtained from experimental information on a ferrotron-loaded spiral antenna at a frequency of operation of 200 MC.

The calculated patterns of the spiral antenna are in general single lobed in a direction perpendicular to the plane of the antenna. The beamwidth varies from 62° …

A Graphical Solution Method For The Tchebychev Elliptic Function Filter, Gene S. Luckfield

Masters Theses

"This thesis is concerned with the design of the Tchebychev elliptic function filter. The Darlington synthesis procedure is discussed and salient points from Darlington's paper needed for the design of this filter are presented.

It is shown that the design of the Tchebychev elliptic function filter requires a knowledge of the elliptic functions, particularly the elliptic sine. Since the use of these functions is not common, a brief review of their properties is presented.

Using the elliptic functions, a development of the equations describing the behavior of the Tchebychev elliptic function filter is given for the case of a normalized …

A Rc Active Delay Time Network., Robert Sun-Wu Han

Masters Theses

"This thesis presents a method for performing an approximate synthesis of a variable delay time network by using RC elements and active analog computer circuits. The delay networks discussed here can provide delay times which range from zero to 96 milliseconds for inputs with frequencies which range between zero 2nd 5 cycles per second.

Basically, the procedure involves approximating the delay time transfer function, e^-jwTd , by the ratio of two polynomials each of which is represented by a finite series of terms. The ratio is then shown to be easily synthesized by RC elements and analog computer circuits. …